Despite modern conveniences, humans continue to transport considerable weight wherever they go. Although on smooth even surfaces, luggage with small wheels is effective, outside of these restricted arenas they are ineffective and add to the weight. Hence backpacks remain the preferred solution to move loads around with us. They are ubiquitous, carried by children and adults, and represent a $295 million dollar/year industry. The large weight of backpacks carried by children is a significant international public health problem (bookbag syndrome). But carrying loads in backpacks also represents a potential problem with adults, particularly the middle-aged and elderly. We now carry more technology (e.g., laptops) and the increased forces can lead to back, neck, shoulder and knee pain &injury which may discourage or prevent people from walking or prevent them from participating in recreational activities (such as hiking). So injury from carrying backpacks can lead to the secondary problem of interfering with activities which maintain cardiovascular health and slow the joint degeneration and muscle atrophy which comes with age. Based on our biomechanical analysis, we have developed a new concept in backpack design, "suspending-the-load". In a recent paper in Nature we have shown that peak dynamic forces can be twice as high as the static force during walking and 3-fold higher during running. Our prototype large volume ergonomic backpack reduces accelerative force by 82% during walking, leading to reduction of the metabolic rate. Our pack further reduces accelerative forces by 86% during running, making it comfortable to run with a load. To bring our innovation to the most affected groups, children and the elderly, we must miniaturize the technology to fit into a much smaller package (a daypack), Further, because weight and portability are issues, it is also important to migrate from an "external-frame" design in our large volume adult backpacks to a light- weight "internal-frame" design which can, for example, fit into school lockers. To achieve this, the following aims must be accomplished. Aim #1. Optimize Ergonomic Suspension mechanism for Adult daypack Aim #2. Design and implementation of wearer interface for internal-frame" ergonomic backpack Aim #3 Testing-Compare ergonomic daypack to normal daypack Aim #4. Evaluate alternative suspension systems for ergonomic backpack Aim #5. Develop a predictive model of the backpack and walking human to help optimize the design By the end Phase I we will have commercialized the adult daypack. Based on the biomechanical and manufacturing insights developed in Phase I, in Phase II we will develop an ergonomic daypack for middle- school students where we will be under greater weight, ease of operation and cost constraints. Phase II: Development of Internal frame ergonomic day pack for middle school students. After developing an Adult Ergonomic Daypack, we will innovate again to build a smaller, lighter and less expensive Ergonomic Daypack for middle school students. PUBLIC HEALTH RELEVANCE: Throughout the western world, it is agreed that the backpacks students carry to school are too heavy, resulting in back and joint pain and injury. Although some of the forces from a load comes from its weight, when we walk or run, these forces can triple, greatly increasing pain and the possibility of injury. Lightning Packs has invented a fundamentally new type of backpack, the suspended-load backpack, which removes the high forces associated with movement. Adult and middle-school daypack versions will be developed here permitting more healthful carriage of loads.